This invention relates to apparatus and a method, for precipitating dust from the air in a region surrounding the area from which dust emanates.
In recent years, and particularly because of governmental air pollution regulations various manufacturers, processors, etc., have been forced to take action to reduce the amount of dust which escapes from their activity. Two examples of activities which present large dust emission problems are the manufacture, or batching, of concrete and rock crushing operations.
Various methods attempting to control dust emissions have been attempted in the past. Such prior methods have either been very expensive or for other reasons have met with little success. Included in such prior attempts are bag houses and water scrubbers using large suction fans, and systems in which large quantities of water are sprayed directly onto the material from which dust would emanate, thus producing a substantial wetting of the base material. Examples of the prior water spray systems include systems where a large quantity of water is sprayed directly onto material on a conveyor belt to prevent dust from emanating therefrom and a system where large quantities of water are sprayed directly onto the material being batched to manufacture concrete. Not only does such a system provide massive amounts of water which must be carried away in some manner, but also produces a significant and undesirable change in the proportion of moisture in either the crushed material or the batched material.
A general object of the invention is to produce novel apparatus for effectively controlling dust emissions, which apparatus is inexpensive to construct and operate.
Another object of the present invention is to provide novel apparatus which is operable to produce a very finely dispersed, fog-like spray of fluid in a region surrounding the area from which dust emanates, thus to precipitate dust particles from the air, without adding significantly to the moisture in the base material from which the dust emanates.
Yet another object is to provide such apparatus in which a surfactant is added to the working fluid in a proportioned ratio, whereby smaller quantities of water may be used with improved dust precipitation occurring.
A further object of the invention is to provide such apparatus in which concentrated surfactant is injected in small quantities into water flowing toward spray nozzles, thus precluding the need for mixing large quantities of surfactant and water prior to use.
A still further object is to provide novel apparatus for precipitating dust from a region surrounding a dust originating area, in which a double curtain of finely dispersed, fog-like spray is provided surrounding the region thus assuring that dust will be captured and precipitated out of the region.